Since the Wilderness Act was passed in 1964, public lands accorded the federal government’s highest level of protection have ranged across 44 states (and Puerto Rico) and covered close to 110 million acres.

On a trail high above western North Carolina’s spectacular Linville Gorge, I’m hacking at the base of a stubborn Carolina rhododendron with a pulaski ax. The trunk and roots of this “rhodo” seem to get broader and stronger the deeper I dig.